ACORUS, in botany, the sweet flag, or sweet rush, a genus of the Monop,-ynia or der, and Hexandria -class of plants, and belonging to the natural orderof Piperitx. There are two species, viz, the A. cala mus, or common sweet rush, of which there are two varieties, the s-uhgaris, or European sweet rush, or calainus aroma ticus, and the Asiaticus or Indian calamus aromaticus. The common cal: anus aro maticus grows naturally on the banks of the rivers, and in shallow standing waters ; and is found in many parts of England. but is much more plentiful in the stand ing waters of Holland, and is common in many other parts of Europe. The Indian columns, which grows not only in marsh ditches, but in more elevated and dry pla ces, in Malabar, Ceylon, Amboyna, and other parts of the East Indies, differs but little from the European, except that it is more tender and narrow, and of a more hot and pungent taste; and A.gramineus, or Chinese sweet-grass, has the roots in tufts, with a few thready fibres. The whole herb has an aromatic smell when bruised, resembling, the English sweet flag, from which it is distinguished by the shortness of that portion of its stalk which is above the spadix, as well as by all its parts, except the florets, being five times smaller than in that plant. It is probably
a native of China, and cultivated, for the sake of its smell, in pots near the habita tions of the Chinese. The sweet flag will succeedvery well inmoist garden ground, but never produces its spikes, unless it grows in water. The dried roots of the calamus aromaticus are commonly import ed from the Levant, though those grown in England 8,re equally good. They have a strong aromatic smell, and a warm pun gent taste ; the flavour is much improved by drying. The powdered root might perhaps supply the place of foreign spices ; and indeed it is the only native aromatic plant of northern elitnates. It is carmina tive and stomachic, and often used a.s an ingredient in bitter infusions.